[sourcecode language="plain"]
[root@tiejiang ~]# cat /etc/centos-release
CentOS Linux release 7.4.1708 (Core)
[root@tiejiang ~]# python -V
Python 2.7.5
[root@tiejiang ~]# ll -l /usr/bin/python*
lrwxrwxrwx. 1 root root 7 Jan 9 2018 /usr/bin/python -> python2
lrwxrwxrwx. 1 root root 9 Jan 9 2018 /usr/bin/python2 -> python2.7
-rwxr-xr-x. 1 root root 7136 Aug 4 2017 /usr/bin/python2.7
[root@tiejiang ~]# cd /home/
[root@tiejiang home]# wget https://www.python.org/ftp/python/2.7.13/Python-2.7.13.tgz
[root@tiejiang home]# tar -zxvf Python-2.7.13.tgz
[root@tiejiang home]# yum install gcc* openssl openssl-devel ncurses-devel.x86_64 bzip2-devel sqlite-devel python-devel zlib

[root@tiejiang home]# cd Python-2.7.13/
[root@tiejiang Python-2.7.13]# ./configure --prefix=/usr/local # [配置]指定可执行文件、库文件、配置文件、资源文件的安装路径。
[root@tiejiang Python-2.7.13]# make
[root@tiejiang Python-2.7.13]# make altinstall # 不要使用make install，否则会覆盖系统自带python
[/sourcecode]

备份旧版本，连接新版本

[sourcecode language="plain"]
[root@tiejiang Python-2.7.13]# mv /usr/bin/python /usr/bin/python2.7.5
[root@tiejiang Python-2.7.13]# ll -l /usr/bin/python*
lrwxrwxrwx 1 root root 9 Aug 14 13:27 /usr/bin/python2 -> python2.7
-rwxr-xr-x 1 root root 7216 Jul 13 21:07 /usr/bin/python2.7
lrwxrwxrwx 1 root root 7 Aug 14 13:27 /usr/bin/python2.7.5 -> python2 # 改为2.7.5
-rwxr-xr-x 1 root root 1835 Jul 13 21:07 /usr/bin/python2.7-config
lrwxrwxrwx 1 root root 16 Aug 14 13:27 /usr/bin/python2-config -> python2.7-config
lrwxrwxrwx 1 root root 14 Aug 14 13:27 /usr/bin/python-config -> python2-config
[root@tiejiang Python-2.7.13]# ln -s /usr/local/bin/python2.7 /usr/bin/python # 增加连接
[root@tiejiang Python-2.7.13]# ll -l /usr/bin/python*
lrwxrwxrwx 1 root root 24 Aug 14 13:32 /usr/bin/python -> /usr/local/bin/python2.7 # 新增的，并指向新安装的python
lrwxrwxrwx 1 root root 9 Aug 14 13:27 /usr/bin/python2 -> python2.7
-rwxr-xr-x 1 root root 7216 Jul 13 21:07 /usr/bin/python2.7
lrwxrwxrwx 1 root root 7 Aug 14 13:27 /usr/bin/python2.7.5 -> python2
-rwxr-xr-x 1 root root 1835 Jul 13 21:07 /usr/bin/python2.7-config
lrwxrwxrwx 1 root root 16 Aug 14 13:27 /usr/bin/python2-config -> python2.7-config
lrwxrwxrwx 1 root root 14 Aug 14 13:27 /usr/bin/python-config -> python2-config
[/sourcecode]

再次检查python版本

[sourcecode language="plain"]
[root@tiejiang Python-2.7.13]# python #正常展示python2.7.13版本
Python 2.7.13 (default, Aug 14 2018, 13:30:06)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
[/sourcecode]

若想访问老版本python(如2.7.5版本)

[sourcecode language="plain"]
[root@tiejiang Python-2.7.13]# python2.7.5
Python 2.7.5 (default, Jul 13 2018, 13:06:57)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
[/sourcecode]

题外话：python2, python2.7访问的是2.7.5还是2.7.13呢

[sourcecode language="plain"]
[root@tiejiang Python-2.7.13]# python2.7
Python 2.7.13 (default, Aug 14 2018, 13:30:06)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
[root@tiejiang Python-2.7.13]# python2
Python 2.7.5 (default, Jul 13 2018, 13:06:57)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
[/sourcecode]

番外：yum的设置(系统预装的yum引用的老版本python)

[sourcecode language="plain"]
[root@tiejiang Python-2.7.13]# yum -y install lrzsz
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

No module named yum

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.7.13 (default, Aug 14 2018, 13:30:06)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)]

If you cannot solve this problem yourself, please go to
the yum faq at:
http://yum.baseurl.org/wiki/Faq
[root@tiejiang Python-2.7.13]# vim /usr/bin/yum
首行的#!/usr/bin/python 改为 #!/usr/bin/python2.7
[root@tiejiang Python-2.7.13]# vi /usr/libexec/urlgrabber-ext-down
首行的#!/usr/bin/python 改为 #!/usr/bin/python2.7
[/sourcecode]